Changes in Bone Health During the First Year of Cancer Treatment in Children

This study aimed to evaluate longitudinal changes in bone mineral density (BMD) and bone mineral content (BMC) in children with cancer during the first year of treatment. Thirty pediatric cancer patients (median age 11.2 [range 3.8-17.4] yr; 21 boys, 9 girls; 19 hematologic malignancies, 11 solid tumors) and 30 healthy controls were enrolled. Dual energy X-ray absorptiometry was performed at baseline and at 1, 6, and 12 mo for each pediatric cancer patient. There were no significant differences in age, sex, body weight, height, body mass index, serum vitamin D levels, BMD, and BMC among children with hematologic malignancies, those with solid tumors, and the controls at baseline. When the medians of BMD Z-scores were compared between different time intervals, whole-body BMD Z-score significantly decreased during the first year of cancer treatment (p = 0.001) in children with hematologic malignancies, especially during the first month (p = 0.002), and between 1 and 6 mo (p = 0.006). In children with solid tumors, whole-body BMD Z-score changed significantly only between 6 and 12 mo after treatment (p = 0.043). Generalized estimation equations for the analysis of trends in the whole-body BMD Z-scores revealed that there were significant downward trends between BMD Z-scores at baseline and those at 12 mo in children with hematologic malignancies and those with solid tumors. Cancer treatment significantly affects the bone health status at least during the first year, causing a significant decrease in BMD, especially during the first 6 mo for patients with hematologic malignancies and during the last 6 mo for those with solid tumors. Better strategies for treating changes in BMD based on the underlying cancer are necessary during cancer treatment in children.